Design: In this protocol we will use standard clinical studies, including neurologic examination, antiepileptic drug levels, clinical neurophysiology (EEG, EMG, evoked potentials, simultaneous Video-EEG monitoring, polysomnography), computed tomography, structural functional, and spectroscopic magnetic resonance imaging, and other studies, such as FDG-PET (performed by nuclear medicine as a clinical procedure) and neuropsychological testing, to evaluate patients referred for uncontrolled or suspected seizures. Tests will be performed in patients when clinically indicated. The protocol will be used to screen patients for inclusion in other protocols, follow the natural history of seizure disorders, and train fellows in the evaluation and treatment of epilepsy. Both inpatients and outpatients will be studied. Standard clinical evaluation and drug treatment of epilepsy is performed under this protocol.